Engine valve mechanism



Oct.7,,l924.' 1,511,203 7 C.- R. SHORT ENGINE VALVE MECHANISM Filed Oct. -18 1923 2 Sheets-Sheet 2' 11' NW N w m W lk; 15 In Wing a W W W- m" M [157m 151F511??? $0.226 I 7 12/34. K M lg 3mm, WM

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Patented Oct. 7 1924. v

UNITED STATES PATENT ()FF-ICE.

CHARLES R. SHORT, F DAYTON, OHIO, ASSIGNOR T0 GENERAL MOTOBS BESEARCH CORPORATION, OF DAYTON, OHIO, A CORPORATION OF DELAWARE.

ENGINE VALVE MECHANISM.

Application filed October 18, 1923. Serial No. 869,243.

To all whom it may concern:

Be it known that 1, CHARLES R. SHORT, a subject of the King of Great Britain, re siding at Dayton, county of Montgomery, and State of Ohio, have invented certaln new and useful Improvements in Engine Valve Mechanism, of which thefollowing is a full, clear, and exact description.

This invention relates to an internal-combustion engine having a poppet valve operated by valve mechanism of the onehead type including a push rod extending from the engine crank case to a point adj acent the cylinder head, and a rocker arm 7 operated by the push rod for operating the valve.

It is among the objects of the present invention to compensate for variations in temperature whereby clearance between the valve and its operating mechanism will remain substantially constant through the agency of apparatus'which is more simple and reliable than employed heretofore.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of embodiment of the present invention is clearly shown.

In the drawings:

Fig. 1 is a fragmentary side elevation of an internal-combustion engine provided in the present invention.

Fig. 2 is a perspective view of a bracket for supporting certain parts of the valve operating mechanism. Q

Fig. 3 is an end view of the engine shown in Fig. 1 looking in the direction of arrow 3 in Fig. 1. I

Fig. 4 is a sectional view on an enlarged scale of the connection between the rocker arm bracket and the engine cylinder head.

In the drawings, an internal-combustion engine includes a plurality of c linders 21 attached to the crank case 22. he cyl inders are provided with cooling fins 24 over which air is drawn into an'air manifold 25 throu h the a ency of an engine driven fan 26.

Fig. 3. The cylinders are connected together in pairs by means of a common superstructure 31 providing intake and exhaust ports and means for guiding all of the valves of the cylinders. The valves are ach cy inder is provided with two valves, one of which is indicated at in maintained on their seats. by means of springs 32 in the usual manner. The superstructure 31 supports a rocker arm bracket 33 comprising lever or foot members 34 joined by a member 36. Each lever 34 is substantially V-shaped, comprising a yoke 34 and branches 34 and 34 joined by a web 35. The branches 34 support a rocker arm shaft 37 maintained in position by screws 38. ,The shaft 37 supports four rocker arms 39, one arm for each of the four valves of a pair of cylinders. The rocker arms are maintained in position by means of springs 40, one spring being located between each pair of rocker arms. Each spring 40 presses one of the rocker arms of each pair against an intermediate boss 41 extending from the oke 36 and presses the other rocker arm of each pair against one of the lever members.

For each valve there is provided a push rod having a foot portion 51 cooperating with a cam 52 on the engine cam shaft. By means of an adjustable ball and socket joint. 53, 54, motion is transmitted from the push rod 50 to the rocker arm 39. The ball 53 is attached to the lower end of a screw 55 threaded into the rocker arm 39 and maintained in adjusted position by nut 56.

Each arm 34 of the levers 34 is attached to the superstructure 31 by means of a link of material having a greater coefficient of expansion than the material of the lever, said links being provided by a pedestal threaded into the superstructure 31 and rovided with a shoulder 61 and a threade extension 62. The extension 62 passes through an aperture in the end of. the lever arm 34- and a nut 63 clamps the lever end against the shoulder 61. he yoke portion 34 of each lever-34 is fulcrumed upon a surface of the superstructure 31 by means of a buta ton 65 having a central aperture and convex spherical surfaces on the opposite sides thereof which cooperate with the companion concave spherical recesses with which the superstructure 31 and the yoke 34 of lever 34 are provided. A bolt 66 passes through a hole 67 in yoke 39 through the washer or button 65, the holes in these parts being larger in diameter than said bolt. In order to prevent the bolt from turning a. lock washer 68 is provided with a series of r fingers, one of which can be turned down as members and another fingersuch as 70 may be bent up ad'acent one ofthe flat surfaces of the head 0 the bolt.

vIt is apparent from the foregoing that a rocker arm bracket is pivoted by means of its foot or lever members upon the cylinder superstructure and that each lever member is connected at one end to a post 60 constituting a tie member between the en inc and the lever member; and, at the ot er end,

each lever member supports the rocker arm shaft.

As the temperature of the engine increases, the cylinder will expand at a greater. rate than the push rod 50 thereby tending to increase the clearance between the push 'rod and rocker arm or between the rocker increase in clearance between the push rod and rocker arm. Conversely when the temperature in the engine decreases there will be a tendency for the clearance to decrease but this tendency is balanced by upward movement of the rocker arm shaft 37 due to the fact that the post 60 contracts faster than V the bracket 33.

While the form of embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be ado ted,

.all coming within the scope of the c aims which follow.

What I claim is as follows:

1. Valve mechanism for engines com ris- 'a point spaced from the cylinder, and a link of material of greater coeflicient of expansion than the material of the lever connecting the engine with the end of the second mentioned lever arm.

v2. Valve mechanism for engines comprising, in combination, a valve, 9. push rod operated by the engine, a rocker arm actuated by said rod for moving said valve, a lever fulcrumed upon a surface of the en inc and havingan arm supporting the rec er arm and another arm terminating at a point spaced from said engine surface, and a link of material of greater coefficient of expansion than the material'of the lever connected with the engine "at said surface and with the end of said second mentioned lever arm.

3. Valve mechanism for engines com rising, in combination, a valve a push ro operated by the engine, a roclfer arm actuated by said rod for. moving said valve, a U- shaped lever having its yoke fulcrum-ed upon the engine one branch of said lever supporting the rocker arm, and a link of material of greater coefiicientof expansion than the material of the lever connected with the engine and with the cm} of the other branch of said U-shaped lev In testimony whereof I hereto aifix my signature.

CHARLES R. SHORT. 

